Yarn spool control mechanism for looms



1963 A. c. NYGREN ETALV 3, 52

YARN SPOOL CONTROL MECHANISM FOR LOOMS Filed Nov. 2'7. 1959 3 Sheets-Sheet 1 71 5229922 A. 3'0? 3 su 30,112, Maw r Jan. 8, 1963 A. c. NYGREN ETAL 3,072,152

YARN SPOOL CONTROL MECHANISM FOR LOOMS 3 Sheets-Sheet 2 Filed NOV. 27, 1959 3, 1963 A. c. NYGREN ETAL 3,072,152

YARN SPOOL CONTROL MECHANISM FOR LOOMS Filed Nov. 27. 1959 3 Sheets-Sheet 3 United States Patent @fliee 3,072,152 Patented Jan. 8, 1963 3,072,152 YARN SPOOL CONTRGL MEQHANHSM FOR LUUMS Arnold C. Nygren and Warren A. Bjorn, Weilesley, Mass, assignors to Shawmnt Engineering Company,

Boston, Mass., a corporation of Massachusetts Filed Nov. 27, 1959, Ser. No. 855,786 2 Claims. (lll. 139--7) This invention relates to pile fabric looms and particularly Axminster looms wherein pile-forming lengths of yarns or tufts are inserted and locked at the fell of the goods as woven. More specifically the invention concerns the control of the spooled and rotatably supported tuft yarn masses in the movement thereof, with the carriers or so-called tube-frames mounting them, through the motions of the successive weaving-in cycles conventional to Axminster looms. It aims to accomplish more certain, accurate and positive control of the tuft yarn spools and hence of the lengths of tuft yarns delivered from them in the weaving process.

In the drawings representing by way of example a pre ferred embodiment of the invention:

FIG. 1 shows in side elevation one end of a tube frame as presented adjacent the weaving station by the carrier chains of a loom, with a frame-handling clutch in approach to the tube frame;

FIG. 2 is a top plan, with parts in horizontal section, generally corresponding to FIG. 1 upon a larger scale and with the clutch engaging the tube frame;

FIG. 3 is an end elevation of the mechanism of FIG. 1;

FIG. 4 is a view partly in plan as viewed from a position above and to the left of FIG. 3 and partly in section as on the line 4-4 of FIG. 3, looking angularly downward in the direction of the arrows;

FIG. 5 is a vertical sectional view as on the line 5-5 of FIG. 2;

FIG. 6 is a horizontal section as on the line 6-6 of FIG. 5;

FIG. 7 is a partly schematic diagram in side elevation of the front or weave end of an Axminster loom illustrating part of the path of the travel of the tube frames on the carrier chains;

FIGS. 8 and 9 are detail diagrams in vertical section lengthwise the warp at the weaving station, FIG. 8 illus trating, the Wipe-in stage and FIG. 9 the start of the lift or draw-off stage;

FIGS. 10 to 13 illustrate a modified form of clutchcarried brake action and control, wherein FIG. 10 is a front elevation,

FIG. 11 a top plan partly in horizontal section, corresponding to FIGS. 1 and 2,

FIG. 12 an end elevation with parts in section, and

FIG. 13 is a vertical cross-sectional view of the electromagnetic brake operating device; and

FIG. 14 is a schematic wiring diagram.

Referring to the drawings in more detail, considering first FIGS. 1 to 6, these represent an end portion of a tube frame 1 equipped tufting yarns Y to be delivered from a mass thereof wound on a tuft yarn spool 3, one end head of which is seen at The illustrated portion of a tube frame 1 and the closely associated Axminster loom parts including one tube frame transfer clutch are those at the right side of the loom. It will be understood that corresponding oppositely disposed parts are provided at the other side of the loom.

Each tube frame 1 is equipped with suspension means for removably attaching it to the carrier chains of the loom, part of one such chain being shown dotted at 5, FIGS. 1, 3 and 5; see also FIG. 7. Any usual or preferred form of such suspension means may be employed, that shown by way of example comprising the hanger or with a row of tubes 2 for the bracket assembly designated generally at 6, vertical blade 7 for entering between carrier the chain 5, a pivoted hook-latch 8 and an upright ear 9 having at the upper end a bearing and keeper 9' for rotatable support of the bearing pintle 3' at the adjacent end of the yarn spool 3. These tube frame attaching or hanger units 6 are fixed on the tube frames 1, one at each end, as by longitudinally projecting feet 6a, 6b, FIG. 6, inserted and secured within the hollow tubular bodies of the frames.

In weaving on Axminster looms, a large number of tube frames such as 1, extending across the loom parallel to the breast beam, are supported at their respective ends upon the carrier chains 5, see FIG. 7, and are caused to travel with the chains in patterned arrangement so as to bring the individual tube frames and the particular spools and tuft yarn supplies thereof into position adjacent the Weaving station at the proper times. At the weaving station each tube frame 1 in turn is engaged by the tube frame transfer mechanism 25, generally and herein called the clutches, and by the latter bodily removed from the carrier chains and taken down toward the warp shed so as to present and wipe in the pendent tuft yarn ends Y between the warp ends, see FIG. 8, for locking in to the fabric by a shot of filling. While still carried by the clutches the tube frame is through the clutch actuating means lifted appropriately to draw off the desired lengths of the tufting yarns, see FIG. 9, such lengths then being cut off by the shear mechanism of the loom and the tube frame returned to the carrier chains and released from the clutches.

In the course of the travel on the loom with the carrier chains the yarn spools 3, 4 of the tube frames 1 are customarily held against rotation, to avoid irregularity in the positioning of the yarns, particularly as to the length of yarn end projection from the yarn guide tubes 2. For this purpose the tube frames customarily are equipped with some form of spool brake, usually bearing against the periphery of the spool heads 4. One form of such tubeframe-carried spool brake is shown for example in FIG. 10, comprising an arcuate pad 10 supported at the free end of an elongate leaf-spring 11 lying along the top of the tube frame bar at the face thereof adjacent the mass of yarns on the spools. Such leaf-type brake is further shown for example in Patent No, 543,080.

Spool brakes of such leaf spring type generally remain applied to the spool heads at all times. Because of their position at the top face of the tube frames they are not readily accessible for mechanical release. They are subject to the objection that if made with sufficient braking strength to approach adequate holding of the yarn spools during travel on the chains they do not permit the spools to turn properly during draw off of the tufting yarns during the weaving operation.

Another form of spool brake carried by the tube frames is of thespring-plunger type such asherein illustrated in the embodiment of FIGS. 1 to 6, noting particularly FIG. 6. These comprise in general an arcuate shoe or pad 12 on a plunger 13 housed in and projecting from the main bar of the tube frame 1 in vertical line with the head 4 of the supported spool. Such brake device during travel of the frames and spools on the chains is urged into brake applying engagement with the spool head as by a coil spring 1 5 surrounding a reduced portion 13 of the plunger 13 and bearing between an upper collar 15 thereon and a lower collar on a sleeve guide 16 slidably receiving the lower end of the plunger.

Such plunger-type spool brakes are generally more efiicient than the leaf spring type mentioned and can be arranged to be wholly or partially released when the clutches take control of the frame. Thus theycan be comprising a link pairs of accorded a sutficiently heavy braking action to hold the spools against turning during travel on the chains.

Heretofore such plunger-type brakes have been operatively associated with the pivoted latches 8 of the tube" frame suspension means 6, or otherwise arranged for intended release by the thrusting action of the clutches themselves attendant on engagement of the latter with the tube frames.

Such manner of mechanical releasing operation of the tube-frame-carried spool brakes solely by the frame contacting action of the clutches has not proven wholly reliable. This we have determined is largely due to the latitude for variation in position of the frames relative to the clutches at the time of engagement by the latter, or other irregularity during contact of the clutches with the latch or other brake-connected means on the tube frame. Resultantly the plunger-carried brake shoe on the frame is frequently but partially released or not at all. In such instances the ensuing irregularity in presentation of the tufting yarn end lengths in the weaving operation is even greater than with non-released but lighter braking action of the mentioned leaf-spring type of brake.

In accordance with the present invention means is provided whereby the plunger-type or similar relatively strong spool brakes of the tube frames are assured of positive release at the proper time attendant on engagement of the clutches. Further, not only are the yarn spools at such time totally relieved of braking by the brake means of the tube frames but subsequently in the course of the weaving in operation the yarn spools are not left entirely free to rotate but are rendered subject to a further brake means apart from that on the tube frames themselves,

and herein carried by and with the tube frame clutches.

Such further brake means is herein adapted to maintain rotation-constraining control of the yarn spools while in the clutches and until the return of the tube frames 1 to' the chains 5, at which time the braking means upon the frames themselves again take charge. Further, such supplemental but correlated spool brake is subject to effective control and may be varied in strength of application at certain times, and may be released wholly or partially during the stages of the wiping-in (FIG. 8) or of lifting withdrawal of the yarn frames (FIG. 9) so as to insure uniformity of action and a constant length of drawoff of the tufting yarns with a minimum of wastage and irregularity.

Accordingly, under the present invention, the spool brake means 12-16 of each tube frame i equipped with an externally accessible release member or finger 17 disposed within and extending outwardly through an opening 18 in a side wall of the tube frame 1, herein the wall at which the series of yarn tubes 2 is located.

In prior brake releases such for example as that of Patent 2,161,762 the brake has been engaged by a lever extension on the hook-latch of the frame suspension means, such as latch 8 hereof. By contrast, and in accordance with the present invention the brake depressor or release finger 17 is operatively independent of reliance on mere mechanical thrusting engagement of the transfer clutch with the frame for taking it from the carrier chains.

Referring again particularly to FIG. 6, the brake release finger 17 herein comprises a bar having an intermediate portion of apertured or yoke-like form so as to straddle the brake plunger 13. The latter has a pin 19 radially projecting at opposite sides beneath this release bar or finger 17 whereby with the brake applied the release finger 17 is supported in the full-line position as in FIG. 6. The inner end of this release finger 17 has an upturned portion 17a whereby it is pivotally associated with an overlying fixed wall in the tube frame, such as the menttioned ear-attaching foot 612. The projecting opposite or outer end 20 of the release finger 17, external to the body wall of the tube frame, is accessible for positive down-thrusting engagement by a motor-actuated element 70 associated with the transfer clutch to be de- 4 scribed. Normally, with the tube frame supported on the carrier chain 5 as in FIGS. 1 and 3, the spool brake 12 is applied to the spool and the release arm 1720 is held up in the full-line position of FIG. 6, through the medium of the relatively strong coil spring 14 described.

One of the transfer clutches, that for the righthand side of the loom, is shown in each of FIGS. 1 to 6. It is understood that a similar but oppositely facing clutch is provided at the other or left side of the loom. The supporting transfer member or clutch proper previously mentioned and designated generally at 25 in all respects other than herein pointed out may be of the construction and arrangement usual in the equipment of Axminster looms. Such clutch proper 25 as shown comprises a cup or scoop-like element open at the top and at the inner portion adjacent the end of the tube frame. It is of general U-shape in transverse vertical section, or as viewed from the left in FIG. 1, and include a bottom wall 26 with downturned arcuate lips 26a for guiding the clutch beneath the adjacent end of the tube frame, and opposite side walls 27, 28 forming with the bottom wall 26 a receiving seat for the tube frame.

As evident in FIG. 1, also FIGS. 5 and 6, the front side wall 28 herein is recessed or of reduced height to accommodate the mentioned actuating means 70 for release of the frame-carried spool brake means. This U- form or cup-like clutch 25 further comprises a main intermediate or transverse outer wall 25a forming the body of the clutch and having the novel control mechanism to be described mounted thereon.

The described clutch 25 is operatively disposed upon the loom in the known manner by means of a main supporting stud 29, FIGS. 1, 2 and 5, rockably received at the upper end of the usual cam-operated clutch lever (not shown) of the loom and by which the clutch as a whole is motivated in the weaving operation. Thus as customary the clutch is adapted to be moved in toward and for supporting engagement with the adjacent end of a tube frame 1, toward the left in FIG. 1, then through the tuft-yarn presenting, wiping-in and withdrawing motions of the weaving operation, including pivotal movement about the clutch-supporting stud 29, and finally an outward return movement, to the right in the position of FIG. 1, after replacing the tube frame upon the carrier chain 5. Pivotal or rocking portions of clutch motion are accomplished by another cam-controlled arm (not shown) of the standard loom equipment operatively connected to a second or rocker post 30, FIGS. 2, 3 and 4, projecting longitudinally outward from the rear wall of the clutch proper, and whereby as in the wiping-in stage, FIG. 8, the clutch may be rocked about the main stud 29 as a center.

In further accordance with the present invention there is provided in association with such transfer clutches, and herein carried on and by them, a second and opera.- tively independent spool brake means adapted to take over and apply yarn-tension rotation retarding and controlling braking pressure to the spool while the tube frame is supported and manipulated by the transfer clutches. And in this connection there is further supplied on each transfer clutch a first and a second motor means, shown as of the fluid or hydraulic type whereby the first brake means, that described on the tube frame is positively released and in timed correlation therewith the second brake means upon the clutch is appropriately applied.

As herein illustrated such secondary or clutch-carried brake and the first and second motor means are mounted on the mentioned body or outer wall 25a of the clutch proper, as through the medium of a casting or bracket 35 best seen as a whole in FIG. 3 and comprising a generally rectangular attaching portion 36 and a laterally projective portion 37. Such bracket as a Whole may be formed integrally, welded or otherwise secured to the clutch proper and is provided with apertures for threaded reception of the mentioned supporting and pivot studs 29 and 30 of the clutch proper, if desired as anchoring means spect to the clutch proper.

On the lateral portion 37 of the bracket is fixed a yoke 38 as by screw bolts 39, FIGS. 2 and 4, for pivotally mounting the mentioned clutch-carried brake means. Noting FIGS. 2 and 4, also FIGS. 1 and 3, said means comprises a curved brake pad 40 fitting the rim of the spool head 4. It is carried at one end of a plate 41 longitudinally adjustably connected as by slot and screw connection 42 to one end portion of a rigid arm 43, the other end of which has a sleeve bearing 44 received on a pivot pin 45 held in the yoke 38.

Positive power-actuating means for the clutch-carried brake means 40-45 is shown as a fluid motor built into the casting or bracket 35 and designated generally at 50. Such bracket is formed with a motor chamber 51, FIG. 4, having on the wall adjacent the brake arm 43, medially of the latter, a flanged guide bushing 52 for a motor plunger 53 projecting outwardly through it and having a reduced end operatively connected to the opposite intermediate part of the brake arm 43 in a manner admitting pivotal movement of the brake arm about its pivot 45 under actuation of the motor plunger 53, as by loosely extending the plunger through the arm 43 and holding the arm on the plunger 53 by a Washer and pin as at 54. i The motor chamber 51 is sealed against pressure fluid by a flexible diaphragm 55 held marginally between the inner chamber wall and the mating enclosing wall of a cap-like fluid chamber element 56 removably anchored in sealing relation to the diaphragm 55 as by gasketed screws 57. The diaphragm is centrally cupped for seating of the head 53' of the plunger 53. A compression spring 58 surrounds the plunger within the chamber and bears between the flange of the guide bushing 52 and the plunger head 53', for returning the plunger and brake 40 outwardly away tom the spool head on release of plunger-actuating fluid pressure. The fluid-receiving chamber 56a at the power side of the motor is supplied with pressure fluid from a convenient source on or adjacent the loom, said chamber having an inlet-outlet port 59 with a tubular fitting 60 for attachment of the pressure fluid conductor pipe or tubing, not shown.

The last described spool brake 40-43 and the hydraulic motor means therefor will be understood to be mounted on the clutch device 25, contrasting in this respect with the herein earlier described brakes 12-13 on the tube frames. Such clutch-carried brake 4tl-43 and its motor 50 are seen to be at the front side (toward the loom front) of the body or casting 25a of the clutch 25, see particularly FIGS. 1 and 3. As evident on FIG. 4 the movement of the plunger or actuator 53 of the hydraulic motor 50, for applying the brake 40 and for releasing it for return movement by the spring 58, is in a direction trans- ,verse to the longitudinal axis of the spool frame and the spools thereof. As previously noted, this clutch-carried brake 40-43 is for taking over the spool-braking control when the tube frames 1 are supportively held in or on the clutches of the loom.

In the FIGS. 1 to 6 embodiment of the invention, the loom clutches such as 25 also are equipped with other motor means designated generally at 80, see particularly FIG. 5, for positively releasing the earlier-described spool brake devices such as 12-13 on the tube frames. As stated, when the tube frames 1 are upon the conveyor chains 5 the holding of the spools against rotation is effected by the brake devices 12-13 carried by the tube 'frames. But when each tube frame as successively presented at the weaving station is supportively taken over 'by the loom clutches it is desired that the relatively heavy plunger-type frame-carried brakes 12-13 be released so that the spool-controlling brake action may be taken over by the last described brake means 40-43 mounted on the clutches.

i 1 Accordingly in the embodiment of FIGS. bro 6 the these latter being utilized for the bracket with respool head 4; see also FIG. 6.

clutch 25 is equipped with the further hydraulic motor device designated generally at 80, FIG. 5, for so releasing the tube-frame-carried brake 12-13, and whereby such brake is positively held released during the entire period or weaving cycle while the tube frame is held in the clutches.

Noting particularly FIG. 5, also FIGS. 2 and 3 the motor 30 is on and formed as a part of the clutch-attached casting or bracket 35 previously mentioned, being disposed at the outer or end face of the latter. It comprises a motor chamber 81, FIG. 5, having at the inner end a sleeve guide '82 for the stem of a plunger 83 having at the outer end a head 84 centrally engaging a diaphragm 85 hydraulically sealed within the motor device 80 by a recessed block or plate 86 aflixed as by screw-bolts 86. The diaphragm defines with the plate 86 a sealed chamber 87 for the motivating pressure fluid. Fluid under pressure is admitted to said chamber power-applying side 87 of the motor 89 via a port 88 having a communicating tubular fitting 89 for attachment of a pressure fluid line supplied from a suitable source. When fluid pressure is released a coiled expansion spring 88 surrounding the plunger guide sleeve 82 and bearing between a flange thereon and the plunger head 84 urges the plunger 81 outwardly, toward the right in FIG. 5, to normal inactive position.

This hydraulic motor 80 as illustrated is disposed for movement of the plunger 83 thereof in a general direction paralleling the tube frame 1 and the axis of the spool 3 thereon. The motor plunger 83 cooperates with the break-releasing actuator or hold-ofl actuator 70 already mentioned.

Noting particularly FIG. 5, said actuator is shown as a two-arm lever or bell-crank rockably pivoted as on a stud 71 is a recess 25b of the clutch body 25a. At the inner portion, nearer the tube frame, it has a horizontal projecting nose 72 overlying the frame-carried brake release finger 17-29. The other or vertical arm 73 of the actuator 70 stands with its upper end opposite and in position to be engaged by the motor plunger 83. Spring means normally urges this rocker or actuator 70 clockwise in FIG. 5 so that the nose 72 is elevated at a level above that of the brake-release finger 17-20 on the tube frame. Such spring means is shown as of the torsion or pigtail form having the coiled intermediate portion seated on the outer headed end of the stud 71 on which the actuator '70 is pivotally hung, with one extended end 75 of the spring attached to the arm 73 near the free upper end thereof and the other end 77 anchored against the clutch body 25a.

From the foregoing it will be apparent that when the loom clutches have taken over and are supporting a tube frame removed from the conveyor chains 5, as assumed in FIGS. 2 to 6, then admission of fluid pressure to the motor will cause the plunger or piston 83 thereof to rock the release-actuator 7t) counterclockwise on FIG. 5 thereby to depress the release finger 2'9 and remove the tube-frame-carried brake 12 from braking relative to the Similarly, admission of cause its piston 53 to 40 into holding engagepressure fluid to motor 50 will thrust the clutch-carried brake ment with the spool head 4.

In operation said brake-controlling hydraulic motors 50 and 8t upon the loom clutches 25 receive motivating pressure fluid from the hydraulic system associated with the loom, through tubing lines (not shown) connections at the motor port fittings 6t and 89, the fluid pressure supply lines to each of the motors 5t} and 80 having on and off valve means therefor. Such valving may be controlled either mechanically or electrically through cams such as represented in FIG. 14 operatively disposed on the main loom cam shaft indicated at 90 in the diagrammatic FIG. 7, these cams being timed Withthe clutchcontrol cams of the loom. For the purposes of the present disclosure it is unnecessary further to illustrate the hydraulic system and control valving, such being of the known or preferred form. The separate valve-controlling cams for the motors 5t and S may be such as indicated at 92 and 94, FIG. 14, on said main shaft 9%). In said diagrammatic view it will be understood that the same shaft 90 is shown at both portions of the figure, the cams 92, 94 being coaxial thereon but diagrammed separately for purposes of description.

The controlling cams such as 92, 94 for the respective brake-controlling motors 50 and 80 may be shaped, proportioned and arranged to correlate the operation of said clutch-carried motors during each weaving cycle in such timing as may be desired for the particular weaving operation, type and character of yarns and other attendant circumstances to afford regularity of yarn presentation and equal lengths of the presented yarns.

In some instances, particularly with certain yarns and heavy yarn masses on the spool, it is preferable that both the frame-carried brakes 12 and also the clutch-carried brake 46 be applied during most of each weaving cycle, so that the spools are firmly held while the frames are being manipulated by the clutches. Then at the draw-off stage at least one of the brakes is released, either by activating the motor 80 to retract the frame-carried brake 12, or by deactivating the motor 50 to release the clutchcarried brake 4th, the valve control cams being formed and timed accordingly.

In other weaving operations it is sometimes preferable to use the two brake means alternately, as for example when the brakes are relatively adjusted so that one of them, e.g. the frame-carried brake 12 applies a heavier braking action than the other, e.g. the clutch-carried brake 40. In such instances the motor-valve controlling cams are constructed, arranged and timed so that both motors 80 and 5t) are inactive, with the frame-carried brake 12 accordingly on and the clutch-carried brake 40 off, until the draw-off stage. Thereat both motors are activated, motor 80 accordingly releasing the frame-carried brake 12 and motor Stl simultaneously applying the clutch-carried brake 4%, for a positive but relatively lighter braking action during the draw-off. Or the brakes may be alternated in the opposite order, employing the clutch-carried brake 40 for the period or periods of relatively heavier brake application.

In still other circumstances it may be desirable to release both brakes momentarily in connection with the draw-off operation or a portion thereof. This may be accomplished by adjusting and timing the cams to deactivate the motor 50 and thereby relieve the clutch-carried brake 45 and at the same time to activate the previously inactive motor 31) thereby to depress the actuator '70 for taking off the frame-carried brake 12. For such latter set-up the cams would be approximately as diagrammed on FIG. 14, assuming them to be operating mechanically or otherwise on the motor-controlling hydraulic valves as described in connection with FIGS. 1 to 6 instead of working upon switches of the electromagnetic variablepower brake unit of FIGS. 10 to 13 to be described. Thus assuming that cam 92 of FIG. 14 controls the valve for the motor 89, and being at a dwell portion as shown it has deenergized the motor 50 and released the clutchcarried brake 4%; simultaneously cam 94 being at a rise portion has activated the motor 89 thereby also to release the frame-carried brake 12.

Thus it will be understood that through appropriate formation and timing adjustment of the hydraulic motor valve control cams any desired on and off positions of the two brakes relative to each other may be obtained for any desired periods in each weaving cycle. It is noted that whatever be the order and timing of the braking operations, the actions of application of the clutch-carried brake such as it? and of release of the frame-carried brake such as 12 are positive, under powered actuation by the hydraulic motor means 50 and 89 respectively.

In the further embodiment of FIGS. 10 to 13, and F 14 as I l e to, the clutch 25 is equipped awaits O c; with an electromagnetic motor device designated gen erally at 1% whereby a clutch-carried brake 110 may beapplied and released at desired times and under controlled variable braking pressure.

In this example the tube frame 1 is shown equipped with a spool brake 10 of the earlier mentioned type carried on a leaf spring 11. It may remain in appliedstatus at all times or may be equipped for release by the clutches in taking over the frame, and maybe sup plemented by a plunger-type frame carried brake such as 12. of FIGS. 1 to 6, with connection with the hook latch 8 for release thereby when thrust in toward the tube frame by the clutches in taking the frame from the chains; see FIG. 11 and examples of such frame-carried brakes associated with the tube-frame ears or latches as in- Patents 2,161,761 and 2,161,762.

Braking of the spool during the weaving cycles is in this instance effected, with different braking strength atdifferent times as desired, by a commercially available electromagnetic motor unit 100 having variable torque. capacity as more or less electrical energy is furnished to it. This variable torque motor unit 100 is mounted on a bracket 101 secured to the standard clutch 25 such as previously described in connection with FIGS. 1 'to 6. The unit comprises a magnetic coil 102 on a tubular core 1%, the core containing a rotatably supported shaft 104'- carrying at the upper end above the coil a rotary reciprocable armature plate 105. A clock spring 106 secured at the opposite ends to the shaft 104 and a fixed part of the core unit such as the coil housing biases the plate 105 in one direction. At the top face of the coil housing, between it and the armature plate 165 is a circumferential series of balls 107 disposed in inclined cam grooves 168 at the underface of the plate 105 and the top face of the coil housing respectively. The construction and arrangement is such that when the coil is energized the down pull exercised upon the armature plate 105 causes rotation of the latter by reason of the balls and inclined cam grooves. The unit 100 is so installed that such rotation is in the counter-clockwise direction looking down upon the unit as in FIG. 11. On deenergization of the coil 102 the plate returns reversely in the opposite or clockwise direction under the action of the spring 106. Further, the structure and arrangement of the motor unit 109 is such that the plate-reciprocating action or torque is greater or less in proportion to the amount of electrical energy supplied.

The electromagnetic motor unit 100 acts upon a clutchcarried brake pad 111 on a finger 112 extending from a forked arm 113 pivoted on a post 114 on the motor mounted arm 104 of the clutch 25. The forked end 113 of the arm 113 straddles a crank pin 109 on the torque plate 105. l i

Noting particularly FIG. 11 wherein the brake is shown in full line in applied position, the unit 100 is assumed to have been energized, so that it has turned in the counter-clockwise direction as indicated by the arrow thereby swinging the forked end 113 of the arm 113 in the brake-applying direction, i.e. clockwise with reference to the pivot at the post 114. Upon de-energizing of the motor unit 100 the coil spring reversely returns the-plate and the arm 113, moving the brake 111 to the dotted line off position.

As stated the force of the braking action applied by the electromagnetic motor unit 100 is proportionate to the energy furnished to it. This in turn is controllable as by a rheostat 120, FIG. 14, adapted to be placed in serial circuit with the motor 100 thereby to reduce the energy or alternatively to be cut-out from the motor circuit with corresponding increase of the activating energy supplied.

In the wiring diagram FIG. 14 two alternativecircuits to the motor unit 100 are represented. One of them, at the right of the diagram, is closed or opened by the switch as controlled by the loom cam shaft carried With this circuit closed at switch 125 as shown the rheostat 120 is connected in series with the motor, hence receives relatively lesser energy and applies relatively light braking torque to the rake 1-11. In the other circuit, at the left in FIG. 14, and containing the switch 126 closure of the switch 126 and attendant opening of the period of each weaving cycle and to shift as between relatively heavy braking action and a relatively lighter bral ing action in accordance with the closing or opening of the switches 125, 126, it being further understood that if The electromagnetic brake means of FIGS. to 13 is readily adaptable for automatic adjustment of the degree of braking efiort applied as the yarn packages or masses upon the spools 3 become depleted in the course of an extended weaving operation. With the decreasing yarn supplies and attendant decreasing inertia of the spools the latter tend to run more freely; also with the decreasing diameter of the package a larger angle of turn of the spools is needed for draw-off of a given length of the yarns. Accordingly it is desirable from time to time in the course of an extended weaving operation to modify the braking effort, usually to decrease it to compensate for the package reduction. In FIG. 14 means for this purpose is schematically shown. The carrier chains 5, a portion of which is shown passing about a lower sprocket 5a adjacent the weaving station is provided at substantially spaced interwith a ratchet wheel 122 having the rheostat contact finger 123 fixed for angular movement thereto. Each lug 5x of the carrier chains 5 is thus adapted to step the ratchet wheel 122 one notch and with it to correspondingly move the rheostat finger 23 to reduce the amount of resistance actively in the circuit. Similar automatic reduction of braking strength may be afforded in conjunction with the hyof the fluid pressure regulating type or if preferred the brake-reducing adjustment may be performed manually by the weaver as for example one or more times in the may be dispensed contact arm for greater or less resistance left to the manual operation by the weaver as circumstances dictate.

Our invention is not limited to the particular embodiments thereof illustrated and described herein, and we set forth its scope in our following claims.

We claim:

l. Yarn spool control means for Axminster looms having carrier chains, tube frames thereon rotatably mounting spools of tufting yarns, and transfer clutches for taking the frames from the chains, moving them for yarn presentation and returning them to the chains, said control means comprising a first spool brake means on the tube frames for engaging a given area of the head of a spool thereon for holding the spool against rotation while the frame is on the carrier chains,

a second spool brake means associated with at least one of the transfer clutches for application of holding action on such spool by engagement with another area of the spool head when the tube frame is held by said clutches,

and externally-powered motor means on the corresponding clutch to control application of said second brake means and for effecting release thereof for return of the tube frame to the carrier chains, said control means including a brake-releasing actuator movably mounted on a clutch which has the second brake means associated with it, said actuator adapted for releasing engagement with the first spool brake means when the clutch takes a tube frame from the chains, and externally-powered motor means on the clutch to move said actuator for positively effecting release of said first spool brake means in the taking over of the tube frame by the clutch.

2. Yarn control means according to claim 1 wherein said motor means for the first spool brake means is pressure-fluid operated.

References Cited in the file of this patent 

1. YARN SPOOL CONTROL MEANS FOR AXMINSTER LOOMS HAVING CARRIER CHAINS, TUBE FRAMES THEREON ROTATABLY MOUNTING SPOOLS OF TUFTING YARNS, AND TRANSFER CLUTCHES FOR TAKING THE FRAMES FROM THE CHAINS, MOVING THEM FOR YARN PRESENTATION AND RETURNING THEM TO THE CHAINS, SAID CONTROL MEANS COMPRISING A FIRST SPOOL BRAKE MEANS ON THE TUBE FRAMES FOR ENGAGING A GIVEN AREA OF THE HEAD OF A SPOOL THEREON FOR HOLDING THE SPOOL AGAINST ROTATION WHILE THE FRAME IS ON THE CARRIER CHAINS, A SECOND SPOOL BRAKE MEANS ASSOCIATED WITH AT LEAST ONE OF THE TRANSFER CLUTCHES FOR APPLICATION OF HOLDING ACTION ON SUCH SPOOL BY ENGAGEMENT WITH ANOTHER AREA OF THE SPOOL HEAD WHEN THE TUBE FRAME IS HELD BY SAID CLUTCHES, AND EXTERNALLY-POWERED MOTOR MEANS ON THE CORRESPONDING CLUTCH TO CONTROL APPLICATION OF SAID SECOND BRAKE MEANS AND FOR EFFECTING RELEASE THEREOF FOR RETURN OF THE TUBE FRAME TO THE CARRIER CHAINS, SAID CONTROL MEANS INCLUDING A BRAKE-RELEASING ACTUATOR MOVABLY MOUNTED ON A CLUTCH WHICH HAS THE SECOND BRAKE MEANS ASSOCIATED WITH IT, SAID ACTUATOR ADAPTED FOR RELEASING ENGAGEMENT WITH THE FIRST SPOOL BRAKE MEANS WHEN THE CLUTCH TAKES A TUBE FRAME FROM THE CHAINS, AND EXTERNALLY-POWERED MOTOR MEANS ON THE CLUTCH TO MOVE SAID ACTUATOR FOR POSITIVELY EFFECTING RELEASE OF SAID FIRST SPOOL BRAKE MEANS IN THE TAKING OVER OF THE TUBE FRAME BY THE CLUTCH. 